Hmm... or is that not your own, but a native menu, Page Properties? Defined only english in menus.cfg??
In that case try the english names, although I have no idea if it helps. But special attention with that one, there are 2 of them!
setmenu("Page Pro&perties",...
setmenu("Page &Properties",...
A bit tricky, they appear in different places, guess one in View menu,
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